Matsushita Electric Works, Ltd.

Hiroshi Nishimura

Takeshi Kamoi

Minoru Yamamoto

Yutaka Iwahori

Hiroyasu Eriguchi

Toshiya Kanja

Katsumi Sato

Kiyoaki Uchihashi

Noriyuki Fukumori

Tadahiro Kono

Minorua Maehara

An electric power source device is provided with a current compensating circuit capable of feeding to switching elements included in an inverter circuit currents substantially mutually anti-phase, the current compensating circuit thus reducing the currents flowing to the switching elements and allowing the switching elements of a small current rating to be utilizable.

Power source device

A lighting device for a high-pressure discharge lamp includes an inverter circuit for converting a DC voltage into an AC voltage using a pair of switching elements. The switching elements have a switching frequency for starting the high-pressure discharge lamp that is higher than a resonance frequency of a series resonance circuit connected in parallel with the discharge lamp. However, in a lighted state of the discharge lamp, the switching frequency is lower than the resonance frequency of the resonance circuit and is within a frequency range where acoustic resonance does not occur. The lighted state of the high-pressure discharge lamp is maintained by a voltage across a capacitor in the series resonance circuit.

Stable high frequency high-pressure discharge lamp lighting device

A device for operating a high pressure gas discharge lamp with an electronic ballast having a lamp power factor of substantially 1.0. The device utilizes a lamp equi-luminescence performance curve X which is obtained for the lamp to give a lamp voltage and a lamp wattage that can vary along the curve X while keeping an arc luminescence of an arc developing between electrodes of the lamp at substantially constant level. The arc luminescence is defined as a maximum luminescence of the arc having varying luminescence along the length of the arc. The constant level determined to be the luminescence that the lamp gives at the rated lamp voltage. The curve X is analyzed to determine a specific lamp voltage Va at which curve X gives a maximum lamp wattage Wa. The lamp is operated in accordance with a first load characteristic for controlling to increase the lamp wattage substantially along the lamp performance curve X until the lamp voltage increases to the specific lamp voltage Va. After the lamp voltage increases beyond the specific lamp voltage Va, the lamp is operated in accordance with a second load characteristic for controlling to keep the lamp wattage above the lamp performance curve X but not exceeding the maximum lamp wattage Wa as well as to keep the arc luminescence below a predetermined limit level.

Device for operating a high pressure gas discharge lamp

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Kobe, Japan

Hiroshi Nishimura